SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-43405

An issue was discovered in FusionPBX before 4.5.30.

EXPLOITHIGH 8.8EPSS 35.6%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 35.6%, higher than 98% of all known CVEs. Patch or mitigate before the next change window.

Description

An issue was discovered in FusionPBX before 4.5.30. The fax_extension may have risky characters (it is not constrained to be numeric).

CVSS 3.1
8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
35.63% probability · 98th percentile
Public exploits
1 in Exploit-DB · first 8 November 2021
CISA KEV
Not listed
Affected
fusionpbx/fusionpbx
Source
cve@mitre.org
EPSS trend
0%20%40%3 November 2026: 35.63%3 November 20263 November 2026

EPSS 35.6% since 3 November 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Public exploits (1)

Entries in Exploit-DB that cite this CVE. Links go to the Exploit-DB page and to the file in the public repository; nothing is hosted here. A verified tick means the Exploit-DB team confirmed the exploit works against the stated version.

EDB-IDTitleTypePublishedVerified
EDB-50505source ↗FusionPBX 4.5.29 - Remote Code Execution (RCE) (Authenticated)php · Luskawebapps8 November 2021no

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.